Functional characterization and biological significance of Yersinia pestis lipopolysaccharide biosynthesis genes

Abstract

In silico analysis of available bacterial genomes revealed the phylogenetic proximity levels of enzymes responsible for biosynthesis of lipopolysaccharide (LPS) of Yersinia pestis, the cause of plague, to homologous proteins of closely related Yersinia spp. and some other bacteria (Serratia proteamaculans, Erwinia carotovora, Burkholderia dolosa, Photorhabdus luminescens and others). Isogenic Y. pestis mutants with single or double mutations in 14 genes of LPS biosynthetic pathways were constructed by site-directed mutagenesis on the base of the virulent strain 231 and its attenuated derivative. Using high-resolution electrospray ionization mass spectrometry, the full LPS structures were elucidated in each mutant, and the sequence of monosaccharide transfers in the assembly of the LPS core was inferred. Truncation of the core decreased significantly the resistance of bacteria to normal human serum and polymyxin B, the latter probably as a result of a less efficient incorporation of 4-amino-4-deoxyarabinose into lipid A. Impairing of LPS biosynthesis resulted also in reduction of LPS-dependent enzymatic activities of plasminogen activator and elevation of LD(50) and average survival time in mice and guinea pigs infected with experimental plague. Unraveling correlations between biological properties of bacteria and particular LPS structures may help a better understanding of pathogenesis of plague and implication of appropriate genes as potential molecular targets for treatment of plague.

Molecular Basis of Yersinia enterocolitica Temperature-Dependent Resistance to Antimicrobial Peptides

“…Not surprisingly, Anisimov and coworkers found a correlation between susceptibility to polymyxin B and the aminoarabinose content of Y. pestis lipid A (1). And recently, the contribution of aminoarabinose to polymyxin B resistance in Y. pestis has been conclusively demonstrated (19).…”

Pathogenicity of Yersinia pestis Synthesis of 1-Dephosphorylated Lipid A

“…The lipid A structures of 10013 (⌬lpxP32) and 10031 (⌬rfaC725) (see Fig. S3 and S4 in the supplemental material) were consistent with Y. pestis 231 with an lpxP deletion and a waaC (rfaC) deletion as described by Anisimov et al (47,48). Results showed that there were no significant differences in LcrV levels in whole-cell lysates or in YopM secretion in each of the strains tested, except that the LcrV secretion level was significantly reduced in 10031(pCD1Ap) (see Fig.…”

“…4B). Dentovskaya et al reported that Pla activity was totally abolished in the Y. pestis 231 waaC (rfaC) mutant (48). Pla is an outer membrane protein and plasminogen activator, and its level of synthesis would be expected to affect its activity.…”

Outer Membrane Proteins Ail and OmpF of Yersinia pestis Are Involved in the Adsorption of T7-Related Bacteriophage Yep-phi

“…LPS is the major component of the outer membrane of Gramnegative bacteria and is a surface structure encountering the surrounding environment. The LPS of Y. pestis is O antigen deficient and restricted to the core and lipid A moieties (22). Much of the available detailed information about the receptors of Y. pestis phages focuses on the LPS (15,23).…”

“…Much of the available detailed information about the receptors of Y. pestis phages focuses on the LPS (15,23). The LPS of Y. pestis has been studied extensively in terms of structure, activity, composition, modification, virulence, and assembly (15,(22)(23)(24). The receptor was identified as the LPS of Y. pestis for eight bacteriophages, including L-413C, P2 vir1, PhiJA1, PhiA1122, Pokrovskaya, T7 Yp , Y, and PST (23).…”